SYDNEY (www.nando.net) - From cannibals in the highlands of Papua New
Guinea to European beef eaters, thousands of people have been exposed to
an undetectable disease that could slowly eat holes in their brains before
killing them.

A new book and a British inquiry have
set out to find the true extent of a disease once regarded as a tragic
pathological oddity but which has killed thousands around the world.

Creutzfeldt-Jakob Disease (CJD) is the
human equivalent of mad cow disease and, like its bovine equivalent, it
kills relentlessly and is largely undetectable until after death.

The book "Cannibals, Cows and the
CJD Catastrophe" tells a story its author says begins and ends in
mortuaries and suggests the disease might be spread far wider than was
ever imagined.

"Speculation on how many people
will succumb to the disease from a variety of accidental means of transmission
is fairly useless at this stage," Jennifer Cooke, author of "Cannibals,
Cows and the CJD Catastrophe," told Reuters.

"It will be a long waiting game
because CJD can incubate without displaying symptoms for more than four
decades."

A British inquiry that started last week
was set up after scientists in 1996 linked mad cow disease -- bovine spongiform
encephalopathy or BSE -- to a new variant of CJD (nvCJD).

So far 24 nvCJD cases have been confirmed
in Britain and France but the long incubation period makes it impossible
to predict how many more will be affected.

"The whole population of the United
Kingdom and a good part of Europe have been exposed," Professor Colin
Masters, head of Australia's CJD Registry, told Reuters. "We know
that the material has been widely spread in the human food chain."

From makeshift morgue to British beef
eaters

CJD is a debilitating brain-wasting disease
which Masters describes as similar to Alzheimer's.

The biggest known outbreak of the disease
was among a tribe practising cannibalism in the remote highlands of Papua
New Guinea in the 1950s.

Cooke's book opens with crusading U.S.
doctor Carleton Gajdusek removing the brain of a CJD victim with a carving
knife and handsaw in a storm-tossed makeshift morgue in PNG and goes on
to detail all known forms of the disease.

About 3,000 people from the Fore tribe
in PNG have died from the disease they call "kuru," the local
word for shivering, contracted after eating dead relatives as a mourning
rite.

"At the peak of the epidemic in
the 1950s it was the major cause of death in (Fore) women and children,"
Masters said.

CJD and mad cow disease are the two best
known types of transmissible spongiform encephalopathies (TSEs).

All forms of TSEs have three common threads
-- the agent that activates them is unknown, they all bore microscopic
holes in the brain of their victim, and they are always fatal.

CJD was first identified by German neuropsychiatrists
Hans Creutzfeldt and Alfons Jakobs in the 1920s. Current theories suggest
it is caused by a virus or virus-like agent or a corrupted natural protein
known as a prion.

The agent is not only infectious but
has also been shown to be inheritable in a small number of cases. It has
no cure and no treatment, resists heating to high temperatures, freezing,
burial underground, strong chemicals and medical sterilisation.

Diseases linked to cannibalism

Most TSEs also involve either direct
cannibalism or the re-use of body parts in agriculture or medicine.

Gajdusek's work with the Fore proved
the link to direct cannibalism and won him the 1976 Nobel prize for medicine.

Feeding meal containing TSE-contaminated
sheep and cattle offal to cows has been blamed for the development of mad
cow disease. Scrapie in sheep is a related disease.

In 1996, the BSE-nvCJD prompted widespread
bans on British beef exports, only some of which have been eased.

Links from the medical cannibalisation
of body parts have also been established.

More than 100 people in the United States,
Britain, France, Brazil, Australia and New Zealand died from CJD after
receiving human growth hormone (hGH) injections as children before artificial
hGH became available in 1986.

In Australia, four women died after thousands
were treated with an injectable fertility drug taken from pituitary glands
removed from the brains of bodies in morgues.

British inquiry to examine links

There are concerns the disease might
be transmitted through blood transfusions. Britain has ordered that blood
plasma must be imported where possible after British donors were discovered
to have CJD.

British microbiologist John Pattison,
who established the BSE-nvCJD link, told a conference in Atlanta last week
that he feared a new outbreak of nvCJD through blood transfusions.

A World Health Organisation (WHO) meeting
in Geneva last month was told that the possibility of an epidemic of CJD
over the next 10 to 15 years could not dismissed.

The complexity of the diseases is being
addressed by the British inquiry, under former senior judge Sir Nicholas
Phillips.

So complicated are the issues that the
inquiry, originally set to last 12 months at a cost of about $16 million,
has already been extended to 18 months.

"This is the first time in the world
that a government, as a public health regulator for its population, has
had to examine its own past actions," Cooke said.